Apparatus for mixing oil and air



July 6, 1937. w p, RElBOLDT 2,086,511

APPARATUS FOR MIXING OIL AND AIR Filed Jan. 28, 1936 2 Sheets-Sheet l WILL/AM 12 25/5007 INVENTOR July 6, 1937. w. P. REIBOLDT APPARATUS FOR MIXING OIL AND AIR 2 Sheets-Sheet 2 Filed Jan. 28, 1956 khuxi :9

W/LZ/flMRRE/BOLDT INVENTOR Q AT RNEY Patented July 6, 1937 PATENT OFFICE APPARATUS FOR MIXING OIL AND AIR William P. Reiboldt, Irvington, N. J., assignor of seventy-five per cent to K. I. Clisby, Montclair, N. J.

Application January 28, 1936, Serial No. 61,126

1 Claim.

10 in every way;

The foregoing and other desirable objects are attained in this invention by the novel features of construction, combinations and relations of parts herinafter described, illustrated in the accompanying drawings. and broadly covered in the claim. r

The drawings are primarily illustrative showing a present commercial embodiment of the invention and it is to be understood that the structure may be modified and changed from this disclosure all within the true intent and broad scope of the invention,

Fig. 1 in the drawings is a broken partly sectional and part side elevation view of one simple form of the invention.

Fig. 2 is a broken end elevation of the pump and motor mechanism viewed from the left in Fig. 1.

. Fig. 3 is a broken part vertical sectional view as on substantially the plane of line 33 of Fig. 1, showing particularly the air pump and its connections.

Fig. 4 is an enlarged broken part sectional detail of the oil pump mechanism as on substantially the plane of line 22 of Fig. 1.

Fig. is a broken cross-sectional detail of the oil ump and part of the connected air pump on substantially the plane of line 5-5 of Fig. 2.

Fig. 6 is a broken part sectional detail illus- 0 trating in particular the self-draining oil seepage well between the air pump and motor, the

sectional portion of this view being taken on substantially the plane of line 66 of Fig. 3.

The burnerhead structure is illustrated like 5 that in Reiboldt Patent 2,028,807 of Jan. 28,

1936 and comprising a mixing and preheating chamber I, on the outer face of a base plate 8,

which is applied over the furnace opening and which carries at the opposite face an inwardly 0 and downwardly projecting air preheating hood 9, through which projects a downwardly discharging mixture nozzle IB, extending from the mixing and preheating chamber I.

In the patent referred to, oil and air are separately conducted to the mixing chamber, but

the structure, as disclosed in that patent, is such that air and oil may be conducted to or entered in this mixer in a more or less combined state. In the present disclosure, it is contemplated that oil mixed with some air be conducted into the top of the mixing chamber I, through a single conduit I I, and that the rest of the air necessary for combustion be supplied under atmospheric pressure through the free air inlet I2, in mountin plate 8, to combine with the mixture issuing from nozzle Ii], at the mouth of the downwardly directed air preheating hood 9. The quantity of such free air may be regulated in the present instance, by damper I3, controlling the free air inlet or inlets I2.

The motor is indicated at I4, on a hollow base I5, containing the mixing and pulsation eliminating chamber I6, from which the supply conduit II extends to the burner head.

To pick up what oil may settle out of the mixture in chamber IS, the piping II is shown connected with a downwardly extending passage I'l, having a beveled entrance I8, opening close to the bottom of this chamber.

The air pump I9 which is directly applied to the end of the motor is shown as having a short length of piping 20, extending from the pressure side of the same downwardly into the top of mixing chamber I6.

The structure of the air pump will be readily understood from Figs. 3, 5 and 6, which show this to be of the sliding vane type, consisting of a rotor 2|, on extension of the motor shaft 22, and carrying spring pressed blades 23, slidingly cooperating with the eccentrically related surrounding pump wall 24. Inlet and outlet ports 25, 26, are indicated at the bottom of the pump chamber at the low pressure and high pressure sides of the rotating piston structure. A suction pipe 2'! extending from a suitable point is shown connected with the inlet port and the discharge piping 20, previously referred to is shown connected with the outlet port 26.

The pump impeller is shown as of four-bladed construction and in order that a following blade will not shut oif the suction being exerted by a preceding blade, the pump wall is shown as channelled at 28 (Figs. 3 and 5) from the inlet port up around the suction side to near the maximum clearance or vertical center of the pump.

To prevent possible seepage of fuel oil from the air pump to the motor shaft bearings, a trap is provided consisting as shown in Figs. 3 and 6 of a well or space 29, between the air pump and motor casings, about the motor shaft and closed except for a drainage port 39, in the lower portion of the same, opening into the suction side of the air pump. This construction enables the air pump to drain off any fuel oil away from the motor shaft bearings and thus prevent injury from such oil to the motor shaft bearings, or to the commutator, brushes, or other parts of the motor.

The oil pump disclosed is shown of the gear type having upper and lower meshing gears- 3i, 32, operating in a surrounding pump chamber 33, in the pump casing 3%, said chamber being closed by a cover 35, applied over the exposed face of said casing. The upper gear is shown as bored to receive the end of the motor shaft extension 22, and as having a cross pin 36, engaged by the slotted end by the shaft and whereby said gear is driven from the motor. The lower is an idler gear rotating on a fixed stud N, in the pump chamber. The oil inlet port 38 enters the central portion of the pump chamber at one side above the lower idler gear and below the upper driven gear and similarly the discharge port 39 leaves the opposite side of the pump chamber at a point below the driven gear and above the idler gear. This construction permits of the lower part of the pump chamber serving as a priming well, holding a body of trapped oil, without possibility of such oil leaking back along the motor shaft. 7

Connected with. the discharge port, or with the discharge side of the pump are two outlets, one of them an excess oil return pipe lii, leading back to the oil tank or equivalent and the other a conduit for carrying the oil to be used, into the suction side of the air pump. The return line 30 is shown equipped with a suitable spring loaded relief valve ll.

The conduit for carrying the oil over into the air pump is shown in Figs. 2, 4 and 5, as a passage or port 32, opening from a point adjacent the discharge port 39, to an aligned port 43, in the cover plate 35, Fig. 5, the latter being governed by a valve M, for controlling oil flow through a continuing passage 5, in the cover plate, back into communication with a port 66, in the oil pump casing, opening into the suction side of the air pump, Fig. 3. The air pump is thus caused to exert suction on the fiow from the oil pump, aiding the lift and increasing the effectiveness of the latter to that extent.

The oil passed by the oil pump into the suction side of the air pump is churned up by the latter and forwarded as a mixture of air and oil to the mixing chamber 7, of the burner head either by direct conduit system or by way of an interposed initial mixing chamber such as here indicated at B6.

The heavier oils. such as the burner handles usually contain some semi-solids. These are taken care of in the illustration by a chopper disc il, fastened to the upper pump gear and operating in a cylindrical chamber 48, in the inner face of the cover, Fig. 5, said disc having a port or ports d9, to register with thepassages 42, 53, in the pump casing and cover respectively. In the illustration, the chopper has two such ports diametrically opposite, but it will be understood that the number and location of ports may be varied to fit particular requirements. This chopper interposed in the fuel line also has the effect of intermittently building up and releasing pressure in the oil pump to agitate the oil and prevent any clogging in the system.

The oil pump and air pump are both lubricated by the fuel oil and this oil, by reason of the suction trap at 29, 36, is prevented from reaching the motor. The mixture created by the oil and air pumps may-be fed direct to the mixing head l of the burner or be given a preliminary mixing in the surge chamber l6, shown located directly beneath the motor and two pumps. The pumps form a unit construction with the motor and may be handled as such for shipment and installation purposes.

While separate oil and air conduits may be extended to the mixer at the burner head, as in the co-pending patent first above identified, of which the present is a partial continuation, it may be preferred for some purposes to run both air and oil in a single conduit to the mixer at the burner head, the latter serving in both instances to effect a final combination ready for burning with the air induced at atmospheric pressure at the burner head. Where the first mixing chamber it is employed in conjunction with the mixing chamber at the burner head, a series of mixing operations is effected, desirable for certain heavy oils. By the two stage operation disclosed the air and oil are first given a preliminary mixing in chamber it, for passage through conduit H, and then after reaching the burner head a final mixing is effected in chamber 7, just prior to completing the combustible mixture at the burner nozzle. Oil that may precipitate in the first chamber 56, is picked up at the bevelled entrance to the outlet passage I1, and oil that may drop out of the mixture in chamber 1, will be picked up at the bevelled entrance 52 to the discharge passage 53, in that chamber. These features aid in insuring a proper uniform mixture at the burner nozzle,even with the heavy oils. The mixture is substantially uniform even at starting, avoiding the initial leanness which frequently heretofore has been the cause of damaging explosions. The upper or final mixing chamber l, catchesany oil that may run back from the mixture discharge tube or nozzle iii, thus acting in the nature of a trap which will hold a small quantity of oil ready for atomization at the next operation of the burner.

-This run-back feature prevents drip at the burner tip.

The gear pump is particularly satisfactory for the heavy oils and is simple and inexpensive to manufacture. The chopper disc 4?, carried by the upper gear of the pump, when it closes off the outlet port 52, causes a building up of pressure which aids in the discharge of heavier oil particles and this, with the cutting action of the disc prevents any stoppage which might otherwise stall the motor. The action of the oil pump is furthermore assisted by the air pump because the suction of the air pump is applied to the discharge side of the oil pump. The air pump thus assists the oil pump and no back pressure is possible at any time.

The amount of free air taken in by the air pump may be subject to control, as by provision of a control valve 50 in the air intake 21, Fig. 2, which once properly adjusted, may be secured by a lock nut M. It will be evident that by nearly or entirely closing this valve, the air intake may be nearly or completely out off, to force the air pump to apply its full suction on the discharge side of the oil pump, for instance, for the purpose of initially priming the oil pump. Another special advantage of the machine is that no stufiing boxes or packings are necessary. Any leaking oil is picked up by the air pump which exerts suction both on the oil pump and on the oil trapping chamber 29, Fig. 6, at the motor side of the air pump. Even leakage of lubricating oil from the motor along the armature shaft toward this suction chamber will be picked up and carried away by the air pump, to keep the machine free and clean of external oil.

What is claimed is:

In combination with a mixing chamber, an oil pump, a passage from the pressure side of the oil pump to the suction side of the air pump, a closed air chamber, a conduit from the pressure side of said air pump to said closed air chamber and a pressure conduit from said closed air chamber to said mixing chamber and including an oil entraining nozzle extending to the lower portion of said closed. air chamber.

WILLIAM P. REIBOLDT.

July 6, 1957.

Patent No. 2,086,511.

above m1? .1

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" Cate shoul nform e Signed. an

Leslie Frazer (Sea 

